SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4624fe24561951a44cb111322c238dc61430f769a2f80f6c01194ba86b3e55c3' 
  AND token = 'ARCI5/XaxhLh3r8zdutig1DVCBuLVaUbxRThk2qKjDw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}