SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2eb245429e9602ab5c2690626a5fea5c52da702862ce632d1b3d7b4bafe39109' 
  AND token = 'CDVHwP2YP9BAsr3g9RTeNBkds/WgOCF38JeADlEO6nw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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