SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '99749072b0e8128094fcdc89c21b9ef27021615dc496fb500473f79cb420af7c' 
  AND token = 'vgaTpQ/p4B6Gg1huBDuhJoOoWGbFVagine0IERJXRPk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00050

JSON explain

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