SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2c56616b24c05aa2b2b8f8fd04be9825d387e573a6ae8a402397a98b032931a7' 
  AND token = 'hg6kflAVlRczdspA1JV5GrKOQGe5X3YSsw79IhJUexg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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