SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'beb6d8a91a07cc956ecb8331440bb4cdda19eb62385c2b3714473e7021af68aa' 
  AND token = 'ZuEcdD7eGyWGYhD7Hpl1Kd3eSKXRscFv7vTsFZOfkK8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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