SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '813016721eeb710a42d1ac52ba018f417eef7a4162734a78d82891b3e1c1a06d' 
  AND token = 'CYI4LyZWfslASYuDXvHVB62z6hP9jipxXYjOgmHHKrE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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