SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4453f777982aa4296cda51ed5fd309fe908f95210f0bee0f407fbc5dd8a19068' 
  AND token = '97Bzcev/YbshvLQXFypjQuYUJ06V+nqxbo1Gzy/Du2k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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