SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '073bb50b928a04718eb1a095c21212eb010c4c5a79b1069d01a542c6ed19acd9' 
  AND token = 'fe5K5/eYWLkD0k8qBqd+RiC2r5mIFuDM0+AaJZZTU+g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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