SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd5400bc946983e9430c8886d9df8d77ebf3a83a9b47b80e7743d30940bcedfa8' 
  AND token = 'Y6bXIPBNahHoJRycTkaQejuPbLH+b0uF/xqX+h1SqZo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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