SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '6139636bd972186a17f66d7bbafc2c0b1964eb3ae7513d783adcaa9eea264f28' 
  AND token = 'htc01E/UawJ+KpbYAcFNzMXxz4SPEzo+PZGDe9TWlnY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}