SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dbad589878ff5f8cc8b828457b6e3717b62e14c9c62816f89ca1b2f458b7a2b8' 
  AND token = 'IM/xWbcUP/6JB8WHuWKpPvK5C1pXb+JtBigNH2Ywy74=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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