SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd8df988f0ce850e736d7b3b5827b132ef545d04cee588e1f745b136460084b89' 
  AND token = 'gLqHUFQ0bPV9Cv8cwA1WhjIeKLZhungO3pwRyBHN1aM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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