SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '6ad0ccccfebd23a62eac04b9bd2f52289aeec41823e11c5a6b9c521a7b060894' 
  AND token = 'j4iEgqSZB0YKfRwvRy3aoOWGXW5MTgCgB8LG2B6+JgQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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