SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '368c7bdac7d3b355bfe4f3b83815d13ecb371655e11b0b91da6199e151f5f3cd' 
  AND token = 'hi5EuU5RzYCb5/M4z//GxIsT04C6KN5dSRPvfkh2cjg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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