SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e18bc1bca49cb63f4725bfc7d3a82bc864559f9263f16fa27389a8132754f2ef' 
  AND token = 'ej7FhX+zfM1uyeywAJjKBCPF98GTFCphgtgRea3eAjI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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