SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2fd5fd9c51683485cf15e7d94d23ca30b132890d91ffdc3976b7c09155583985' 
  AND token = 'Shc2YcPEJ9mUB4TWQ5N35yFYHToRJ90+FnEMIGjKkIA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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