SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '80f35daf273a15b3ae9feaf7f711af6e7e22d9b463aa68fe444446e1ad4fe2b5' 
  AND token = 'JEyS+0159w7WfFZEfm3vsIb5CysCV2t62yPPmmJQPeA=' 
  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"
    }
  }
}