SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ebbf4cfd493a197c4767c844b2fd451960d5981445a66f304fabad8f9e84058d' 
  AND token = '5Sfj00bRDbV7lIbDinfKKAt3e5u356dPEVGNheNgiPE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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