SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '86bc08ee5a2ccccf08138b25fe8c1a016c57bd7f87ad46850edc526523cdbd92' 
  AND token = 'T8h0sKYsOm69s/OtOSrsmIKzlnLishhp6TSZjebR4Zc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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