SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '945031368d7c53b132a28b1415730c428d14e62a2ef204dc164d854a65e3d760' 
  AND token = 'NimABTdRhcRbuKU03msHA2E3mdWWKu/TeoTgDa2d7Lk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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