SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bdc7a63e47ecb4012c4eb3240c1553246218541749064aa1ddef19924ef3da21' 
  AND token = 'DPGCdFOUNrm/1viiyqFibUJTtk6sEzZu/dm6pkCpVOo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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