SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0fdef9a0787493eb6ea056f87561ccf457ce27c3ce1eb245df084b80e0ddd4d8' 
  AND token = 'owBTQY+KV3ZL6izsWdMYPxL7zTkRb4YrTGLI7ENmZ2k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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