SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0819a3bec398e72e57c39e5718d0a50c6cad971b65ab9e70b950cba87b2f65f3' 
  AND token = 'HzIkRzzYSCDQBv5VRT8mFAMC+krWW3fhUXjJaeux+LQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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