SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '02c1e9aa4bf8e9d0a8047888b58ecfed2bda70aaad2d77b916aae59d71718e77' 
  AND token = 'ZJ2rSSC9n86vPdQqGGP4SXxbdfcVCqSUVJRpVwmB9Pc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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