SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5f85121f61d3a6c198925a8732377b72d8f04bb2306089dcfe286b6b179b8eff' 
  AND token = 'PYf1hIejpNLJTnqfwbEtcSJYy4+QCwYMsJwu9PN6uPg=' 
  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"
    }
  }
}