SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '5a24530ecd640d303067fbfade67fb70328175ec9bd083b19b04a671a450799a' 
  AND token = 'c/DTMqhYD5sYWGuVmIjePsu+2/7BmQP+vilmFnn+7DY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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