SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a8a59f69d55c107f61b13626253e6c67dcae84189159582f425c8c78a41e862b' 
  AND token = 'cbP/WSvgc6DpY1k7++ij+imQJms9ylpSzvdAoPPS7Ss=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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