SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ce0af316b7945f25dbb86e334485043342aad92f273290f00e09b605eac851f3' 
  AND token = '+UpRWrGlmmDZIudqtlns0vHhcjykFv2iCCEjrJCsZ5E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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