SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9e5f064889d86f87b9af711e979aec02b2c82e36904ad474c30d2b24c2b4b4c5' 
  AND token = 'JM2gKHTtkpVXYtUUjMhlgw1RJXuzY8bMPXUqrNUy8sU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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