SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '61d077f098ae504f041d136d5c92df5c87c87d299fa87970aedac20244acc137' 
  AND token = 'UYnFO535ndQyQbAn+XZyjZOTtNsAtEDcsmDz06wk8rw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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