SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e6ae2f8243f363edb6ad45c63f77a0c3856d79b2b8c012745286597b95a8127d' 
  AND token = '9QIQBCTxjl+2HlTLGFpi79q+Fm3YuP++mWjfzUlwCs0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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