SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2766e869bd5e1b1959fd6c3d5bf8588f0a83208292ccacd9f92d98fc915d83bb' 
  AND token = 'zwqJZqTgqoK4Ljc/bCuWL4DFZMGlkziTWN8stWgMg/g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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