SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd3436da70a2aa68086cda92d7106497ff5ad2b4edf61f38cf067a06b13260fd3' 
  AND token = 'Edt+vSsGnnYGCKc0lcxQPYJZpWesRsl+eUV7jcyrKJ0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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