SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f01cacc39ae5db49b9ae17baf9050872e6313cdc23e8fbf711cb2f5098a75b8c' 
  AND token = '/CaQMi2wp1FjMrhnpsyDN92RMXNSsSAxqlp9ysAkC5U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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