Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'df93d03cdef441e6a377bcd0c824682e0a142b28f4412b5ca2ebbeaa7d27e7f2' 
  AND token = '6hZpmxHtezCVw8JpAFJt1pAntRqtJuy/4l+8j/XLeo4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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