SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '48ff595cefcdffd479f316a705545e4afb0b0ef015ad7071431252e8e6a579ce' 
  AND token = 'NGqqImngQHGfDvyT1lGW7pwT6eKPCIqA3sLjUDRy23Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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