SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f66efeedac7c6188439bd9f79785e1d14239baa790c828d67f444759c069c2fc' 
  AND token = 'GhVmKxpBnZufOqZ0qr9rdlN6JrZgVPIXX1H62d2Z5P8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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