SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '08b9cd2b8c3eb58248a4d3086e3ff29d8492b22612a725cbce3cc0e30634b541' 
  AND token = '05BTRdMaFv2utHBF/KHt0KGhjP6UkuVzqXpbuEoeVnk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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