SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cf4c0f5cef41b31e803e019dcc815e5cc2d02da6bec69a4c94940c76a8833071' 
  AND token = 'RKRPu6edcadRpwc4IlkwK7159/Cb8greTCCxXujRQdY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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