SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f78db61202feccee7002bae497ceb8652116f8d99d64c52d70bfeb40562874a6' 
  AND token = 'jxbe5Wj9s6L2OJp1gIOGNLPI55LaiS0WJjmkT1nHCWo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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