SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2d06805e646869d5c945fff07f60e21dca85a928118e7c30f26f7d099a72033f' 
  AND token = 'W2FnAX+UwoE1xa6oOzrEfvVxRZJAKvAlKwENzynpqoQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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