SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b00cee99496abc75e518ca3d7a8a89037c7c263885c0fef1e348450e62c70398' 
  AND token = 'xVXNlFqyRgfJ+Z9+/ouMKt6Ihr72tCviEffsF2UZHhU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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