SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '187dda2e9159f6edeaffeca940a353d8e00aed4ca347c759f0a652e1b70fcd26' 
  AND token = 'BXQB0N2rRBGdnO3O+p2aW21wcqp8nBfjpRmlcujQOnY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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