SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '97441cd296da0e25a2f512dccad2d6859fb9a986e082ffee9421a4e6841a1b31' 
  AND token = '6GtqhlderQkbdXSkdW4BUMd58B/8M7oV+GGH1McCioo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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