SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7f6e098bc98a637bbbf299e493bf990db25aff56eb06ca78e2782aba73bcc1a1' 
  AND token = '13/iAPN8M2c6eEhl3H7IoLydPhF9WwY6Mdwj/g67Nng=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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