SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd4ad1a0492e847b14c5f7391208489721b6e0ac295b3e46fe2841d3eed90f69f' 
  AND token = 'fstVaOHLERp9c+TCwz7JdLHr0QNhHEIffjLZRirHYt0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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