SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd1c7f9112ecdcaddde47a91959d94d4b5f0820e4783953813700a01c85894294' 
  AND token = 'wxh2l3Uyz1ckVqiPTRoSQVQBWpaHWRBqfAUIQ9XQSyY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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