SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'f8e7aa918e2255d35e73ef42a396ecabc56b170a3f683d73de8ebd27e4a22278' 
  AND token = 'kRgZy9t2w+H+/7TqIt3FkzFqwcijYwfhKNOLE8ndVno=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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