SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9003a74834834d3bd61c74b1e57483dab14cfa92e6c358a89d6a91bec25061f8' 
  AND token = 'RqHMK2PQgm3TF7gZnqyJI+QzgX08qv+0yVT3apVv1Jw=' 
  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"
    }
  }
}