SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '201ac3cf30b794718bd570591959a18d1c2be419d01f6bf3b6f4b920140d08b4' 
  AND token = 'X5YBy/wbStCBAOpV0yLvLKjkLDPtjLqFnm9+na+6oxw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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