SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6016368a4fde421af7e44242bf110cd99d6052128b0f53eacc229926c8fb9762' 
  AND token = 'qd5t8E6yuCuBWPwdRi7RGEBJ7oXf0WkboifcPf2zk2c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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