SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4a947698759a0e8b3625cbac21182c016fdb6ac3e9cf97aaa163b4d09860e5da' 
  AND token = 'tvJJkKtC/pIBFGz1Y+H81b+Rv4Pg2Pv7o6q2id8uO4M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}