SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bad500f14c542cee082a6feb31b3feaa79709b08d6cac9b66f0ded782e030236' 
  AND token = 'd6JTUC/2pJuHzPNTySGE1eUqxiDZWvPZVExGt2301IE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}