SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7e5405a57f631ff0f1b7ec5c025081d9b7af6fecf9a4c9654fe25ce4b63e027c' 
  AND token = 'pbJEpPbGW8ZGWAXWpJ0RDLlpQm1k5981Y1lnZSD48qc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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