SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9cb7166188ad6a85068712d571a5f23f4692fd14767f17f00e8d76149e4546b9' 
  AND token = 'H16XNRnbYdhaKVT0pzfQEeuZJsgfSO5z2JXCmFTEsn4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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