SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '44fdd66ab97b59ea94c50eb683394332bf13ff856a3abc26d73203d15db76be2' 
  AND token = 'UvcAXvuWK0kyxdQiKg9NKTFCEseeH6nZr92oxjLicB0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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