SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a09e31211b38fdadd5e1566d7aa9b674bad09218e8969ad211018fc18832c2db' 
  AND token = 'BBJUclNrHr/gnfvrkmtmXfcuo6GPYWRbMpsf5Jtm/j4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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