SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dbdaf9de2ba8126164fe9cc4b444449bd80b373c99a92d89ce771b440aa6a39c' 
  AND token = 'yGn6CQjgyoFvPyrf178zUtx93HFUwzo3dPBdBK6e7Is=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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