SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8eb125d4ae00658c21c7023c64695fda8dae4da3df34fd9f7a8cd42814a2f4e2' 
  AND token = 'bCqlt9m9hE03kJbLN+zvutqGBYmAVnaE1CmkvpvZ9kU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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