SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f4057980f1c042dbc6f564e6dbae58d53e3ff95a747d4061ffc750cf8144185c' 
  AND token = 'fR1NRjMUsEFlEjFQhHR4Y9L+2DbDs/sEmdzRGDa+RqE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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