SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '37970468479112e7a222a3fa8ff7fd165feffa5ec625cd28648f56181c0637a6' 
  AND token = 'ngaaB26HgRGVeJHma6rH/kYnn7Se5CQo0nWzRgoKqjY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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