SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6be7fe9143d8754f92279593fec58abc776f4b5dfb5d74a9c05392f7f95f6258' 
  AND token = 'bqfEfYbdywIl0qJ5Q5sZaCPVl9pIz/2Pm3yCcME7ymg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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