SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ecaac3fd047ab19c10ee7add339dc5c81067e37ee022fb7d499e2d1bbc25d50c' 
  AND token = 'JK/Ul06//EKzAoGhgS6sHqJakXFOqYpMD/7kSno22oI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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