SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'f5818a55850a9c34885c135b0689c7844e422e6453b7e19d9c271704286e15e5' 
  AND token = 'JwYgKCVWtrmS0vyavXVdqP2HJT4O+hQ/CW0Y3XJHZf8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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