SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7c8448fc1b519768329e2be7302dcaba3275601b578f80d11dd42acc76e4791a' 
  AND token = 'T1aD5CEZwqSwS9z01F9qxe6McUgsLBgITSG6y5NYMuE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00068

JSON explain

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