SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '63137995a540ad2d369dad5aa40a074f40df848c5bb09e9ab737eb530a987cf7' 
  AND token = 'NmdJIbLsNCfdHw8aGaR7X/jvYlTIAKkIB3gpMaACZJc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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