SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1631390ceb8cf08482f7f69c874645e3821094163dad1c2b68681ab57f808574' 
  AND token = 'URMudUvOcTu8FjyMzwl8JwQpYP+laA01Fp7qjRfqju4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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