SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bc6b92bcecd38a8ba28eca48ceb761a3e5892152ee64f23cd5ff7cfca1184a7a' 
  AND token = '9+8YvVnG++wAJeJnSVBeRASFzGoV6UQlrEhFj4ZtNTk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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