SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'ab788444d540e3e88b7b219ec199485019143ddf962cae3a47f624694229a8b8' 
  AND token = '2tQukwyKwfRL1K3p+fULcFUf2iUpDWI0sUERKXrB6CY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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