SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '72626b3fbc45f05c389fb6eba5457795d68937303b61f26c706c1f3b8248f3f2' 
  AND token = 'BZzuc72jFQrosJdMfFdNndcC5kXbKbAyeCEiRivXNaQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

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