SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '74965e9e90a4a4571a7db041fcd063835c25deeffe0f087b140f35dd7a87db63' 
  AND token = '/3y2DF5ocSAKtSQuxLKtthsiZR8i6NgLJwPrbJITiZg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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