SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c47964a3d78e6d04011536e7e51be2b2a5aafc860391fce2bd94cf67e5d09217' 
  AND token = 'FFhn3k1dqPrRfR3JTWW3vfer0Kpfmq2BaIiYO2xf7Pc=' 
  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"
    }
  }
}