SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cbd293f86e6c45449636e2734146c6e89c0a61ba40fc811b1d93978feaef7efe' 
  AND token = 'XTbkgsQJdIIqmXbsgwgnzo4R0PQcf1gP/IMJnhOY2Bg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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